For example, apparatuses which can be driven with power supplied from external power supplies such as commercial power supplies and power supplied from batteries serving as auxiliary power supplies have appeared. When the apparatuses are configured to be drivable with power supplied from batteries, the apparatuses can be drive even during emergencies in which power normally supplied from external power supplies is not supplied to the apparatuses, for example, during a power failure.
Technologies for controlling operations of apparatuses through communication via power lines have been developed. An example of a technology for controlling an operation of an illuminator through communication via a power line includes a technology disclosed in Patent Literature 1.